Refrigeration



.A. A. KUCHER 2,132,534

REFRIGERATION Original Filed May 1, 1933 Oct. 11,1938.

4 Sheets-Sheet l Oct. 11, 1938. A. A. KUCHER 2,132,534

REFRIGERATION Original Filed May 1, 1933 4 4 Shgets-Sheet 2 Oct. 11,1938. v A. A. KUCH ER 2,132,534

REFRIGERATION Original Filed May 1, 1933 4 Sheets-Sheet 3 Oct. 11, 1938. A. A. KUCHER' I 4 REFRI GERATI ON Original Filed .May 1, 1955" 4 Sheets-Sheet 4 Patented Oct. ll,

PATENT OFFICE REFRIGERATION Andrew A. Kucher, Daytom'Ohio, assignor, by mesne assignments, to General Motors Corporation, a corporation of Delaware Application May 1, 1933, Serial No. 668,771

Renewed October 23, 1937 14 Claims.

This invention relates to refrigeration.

An object of the invention is to provide an improved arrangement of the parts of a refrigcrating system to simplify the operation thereof and at the same time enhance the efficiency of p the system.

Another object of this invention is to coordinate a refrigerating system with the cabinet to be refrigerated thereby in such a manner that the food preserving space of the cabinet is emciently maintained at food preserving temperatures by a system of relatively small refrigerating capacity and in such a manner that the refrigerating capacity of the system can be concentrated. temporarily to freeze substances in the freezing space of the cabinet Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:- Fig. 1. is a. view partly diagrammatic and partly cross-sectional, and partly in perspective,- of a refrigerating system embodying features of my invention;

Fig. 2 is a front elevation of a refrigerating cabinet including a system as shown in Fig. l and embodying features .of my invention;

Fig. 3 is a view transverse to Fig. 2;

Fig. 4 is a diagrammatic view showing a certain phase of operation 'of the refrigerating system;

Fig. 5 is a view similar to Fig. 4, but-showing '35 a different phase of the operation of the refrigerating system;

Fig. 6 is a vertical cross-sectional view of an evaporator embodying features of my invention;

Fig. 7 is a horizontal cross-sectional view of 4 the evaporator shown in Fig. 6;

Fig. 8 is a top plan view of the evaporator;

Fig. 9 is a side elevation of the evaporator;

Fig. 10 is an end view of the evaporator; and

Fig. 11 is a cross-sectional view of theh'efrig- 45 erant restrictor or expander.

An apparatus embodying features of my invention includes in general a cabinet to having afood preserving space H and a freezing space l2. Associated with this cabinet is a refrigerat- 50 ing system of the type shown in Fig. 1. This system includes a motor-compressor unit 13, a condenser l4 and an evaporator 15 in closed refrigerant circulation relationship. The system may be associated with the cabinet in any suitable manner. Thus the motor-compressor unit from the food preserving space H.

The system isso coordinated with the cabinet,

that it is adapted to maintain the proper temperatures in the food preserving space, preferably above 32 F., and the proper freezing temperatures in the freezing space H, preferably far below 32 F.

. The evaporator is so constructed, that it directs or concentrates preferentially the freezing power 3 of the system into the freezing space, so that liquids or articles may be frozen in arelatively short time and before the cabinet and its contents are likely to warm up above the permissible upper limit of food'preserving temperatures. To this end, the evaporator is provided with one or more freezing shelves It and ill, and if desired,- the bottom l8 of the evaporator itself may be so shaped that it forms a shelf upon which ice cube trays or the like may be placed. These shelves each have a reservoir for maintaining a quantity of liquid refrigerant therein, which refrigerant is available for quick freezing when articles to be frozen are introduced into the freezing space. 'In one form, these shelves are made by securing together two metal sheets, the lower one of which is corrugated, to provide a sinuous reservoir it on the lower side of the shelf. The reservoir it is provided with means to maintain a quantity of liquid refrigerant in the reservoir and this means may take the form of a dam or upstanding pipe 26, the overflow edge of which is above the bottom of the reservoir it. The reservoir it on shelf it overflows into the reservoir 2B of the shelf ill which is also formed with'a sinuous reservoir terminating at the overflow discharge pipe 22 having an upstanding intake similar to that of pipe 2ll, and the pipe 22 discharges into the bottom of the evaporator at 23. The bottom of the evaporator itself forms a refrigerant reservoir it which has substantially the same action as reservoirs l9 and 2!. These shelves may be made in any suitable manner and preferably the sheets forming the shelves are welded together at the places where they contact with each other. I

A refrigerant expanding device is positioned between the condenser i4 and the evaporator, so that it introduces liquid refrigerant first into the freezing shelves. To this end, the pipe from 55 the condenser I3 passes through an interchanger 25 in the gaseous space of the evaporator and then discharges into the refrigerant expander or flow restrictor 26 which in turn discharges the expanded refrigerant through the pipe 21 into the shelf IS. The expander 26 is preferably in the form of a fixed elongated orifice, for example of the type shown in Fig. 11.

In Fig. 11, the expander is provided with an inlet 30 which is connected to the interior portion of a cylindrical screen 3L;- passing through the screen enters one or more passageways 32 leading to the helical groove 33 formed on the inner cylindrical member 34. This groove is covered by the outer cylindrical member 35 which is preferably placed over the member 34 by shrinking itthereon, the member 35 being heated sufficiently to provide a loose fit over the member 34 during the telescoping operation, but which shrinks to a tight fit when the temperatures of the two members have been equalized. A sleeve 36 is placed on the interior of member 34, and during the manufacture of the expander, this sleeve may be moved axially to cover or uncover one or more of the passages 32 which are placed at intervals at one end of the member 34, so that the effective length of the groove 33 may be varied to the desired extent. After the desired length of groove has been obtained, the sleeve 34 may be soldered in position. This calibrating operation may be performed before the inlet cap member 38 is-assembled in the device, the calibration being performed by creating a vacuum at the discharge outlet 39 and determining the flow occurring through the elongated orifice or groove 33, and calibrating it by moving the sleeve 36 to the desired position before the cap 38 is inserted and soldered to the cylindrical member 35.

The food preserving space H is refrigerated by the food storage cooling portion of the evaporator. Preferably this food storage cooling portion of the evaporator is so formed as to insulate the freezing space l2 from the food preserving space H and to prevent or limit the. interflow of air between these two spaces. This portion of the evaporator is preferably made in the form of a relatively fiat refrigerating chamber 40 formed by welding together two metal sheets 4| and 42,'

the outer one of which is corrugated to form vertical passageways 40a in the evaporator, and the intermediate portions 43 of which may be welded together in a well-known manner. The portion or header 23 at the lower part of the evaporator extends substantially throughout the entire length of the evaporator, the passageways connecting and terminating at this header. At the upper portion of the evaporator two headers 44 and 45 are provided, these headers being connected by means of a pipe 46. The header 45, together with a portion of the pipe 24 form the interchanger 25 for pre-cooling the unexpanded refrigerant flowing from the condenser H to the expander 26.- The evaporated refrigerant flows through the header 45 through the pipe 41 to the motor-compressor unit i3.

The construction is such that expanded refrigerant passing through the pipe 21, which refrigerant is partly liquid and partly gaseous, deposits the liquid refrigerant in the reservoirs 19, 2| and I8, and the liquid refrigerant rises to a certain extent in the passageways 40a for cooling the food preserving space. Depending on the temperature conditions outside the cabinet, which create varying head pressures in the pipe 24, the

Refrigerant duced onto any of the shelves l6, l1 and I8.

level of liquid refrigerant in the passageways 40a rises and falls to provide more or less refrigeration for the food preserving space H as required. by the heat leak into the cabinet. By

so placing the expander 26 in a relatively cold part of the refrigerator, and particularly by protecting it against the wide variations of outside temperatures, the liquid refrigerant does not tend to gasify while passing through the orifice 33.

to the same extent which it would if this restrictor were placed outside of the cabinet and where subjected to wide variations in temperature. It is desirable to permit a relatively large quantity of refrigerant to pass through the expander during warm days, and since the total mass of refrigerant in the form of liquid passes more easily than refrigerant in gaseous condition, the position of the restrictor in the cabinetis made to minimize the formation of gaseous refrigerant in the restrictor on hot days.

The condenser is so corelated with the refrigerating system, that it tends to create higher head pressures when abnormal refrigeration demands are made on the system, such as when freezing trays with unfrozen liquids are intro- To this end, the amount of refrigerant in the system is so corelated with the volumetric capacity of the system that during normal operation the liquid refrigerant in the condenser l4 stands at or near the lower receiver 50. The condenser i4 is so shaped, that if a large quantity of refrigerant should be evaporated from the evaporator and be transmitted through'the compressor, the con-' densed refrigerant will rise in the portion of the condenser lying between the receiver 50 and the upper receiver 5|. This elevation of the liquid refrigerant level in the condenser blankets its effective condensing area and thus reduces the condensing capacity of the condenser. This in turn creates higher head pressures in the pipe 24' and therefore forces more liquid refrigerant intp the evaporator. This increased flow of refrigerant in the system increases the refrigerating capacity of the entire system and particularly in the freezing shelves, so that any substance inserted to be frozen is subjected to this enhanced refrigerating effect. The size of the upper receiver 5| is so made that it prevents the rise of liquid refrigerant above this receiver and thus prevents the blanketing of too much condensing area to produce harmful effects in the system.

The foregoing action of the system is diagrammatically indicated in Figs. 4 and 5. In Fig. 4 the level of liquid refrigerant in the condenser is indicated at 52. This level, with slight variations,v is the normal level and when the system is operating without heavy demands such as when there is no substance to be frozen, or when the substances which have been inserted have been properly frozen. Fig. 5 indicates the condition of the system when substances to be frozen such as trays 53, 54 and/or 55 are inserted with water to be frozen. Under such conditions, a heavy evaporating action is immediately set up in the reservoirs l9. 2| and/or l8 which forwards a large quantity of evaporated refrigerant to the compressor and in turn to the condenser, and this action fills up the condenser to a point 56, varying in level under varying conditions, thus blanketing the effective condensing area of the condenser to increase the pressure as heretofore described.

The length and cross-sectional area of the restrictor elongated orifice 33 may be made or calibrated as described in my copending application Serial No. 599,239 so that'the motor-com-.

pressor unit l3 vmay operate continuously throughout the entire normal room temperature rangeand yet maintain foodpreserving temperatures in the food compartment I l and freezing temperatures in the freezing compartment l2. However, it is not necessary to the practice of many features of the invention herein described and claimed that the elongated orifice should be'calibrated to the extent described in the said copending application; and it is within the purview of this invention that the calibration be carried only to the extent that the motorcompressor unit l3 operates continuouslyonly at the higher normal room temperatures, and intermittently at the lower room temperatures. In fact, many advantages of this invention are attained even when the size or calibration of the elongated orifice is such that the unit l3-operates intermittently at all normal room temperatures.

Accordingly a thermostatic control 60 may be provided for starting and stopping the motorcompressor unit l3, and this control may be so set that, depending on the calibration of the restrictor, the unit 13 operates intermittently only when room temperatures drop below those normally maintained in a household, such as when they drop below, say 50 to 65 F. The control 60, on the other hand, may be so set that the motor-compressor unit becomes intermittent when the room temperatures drop below a much higher limit, such as 70, 80, or in fact, if the restrictor calibrations warrant or require it, the control setting may make the unit I3 intermittent throughout the entire normal room temperature range.

The thermostatic control 60 may be in the form of a thermostatic snap switch 6| having a thermostatic bulb 62 placed in aposition on the evaporator such that it is responsive to the temperature of the food compartment ll. Thus, if the bulb 62 is placed substantially as shown in the drawings, it will prevent the temperature of the food compartment from falling below 32 F., or any lower temperature limit to which the switch is calibrated. The switch 6|, in response to food compartment temperatures, opens and closes the circuit 63 leading to the starting relay or control box 64 which in turn controls the current flowing to the windings of the motor in unit I3. Controls of the type indicated at 64' automatically control the flowof current to the motor so that the properwindings are energized during the starting period and the proper windings are energized during the normalrunning period after the motor has started. Thus, if the motor is of the split phase type, the control 64 energizes both the running or main winding and the phase or starting winding when the switch 6| closes and thereafter opens the circuit to the starting or phase winding after the motor .has started. The type of control indicatedat 64 is now well known and is therefore not further described. 7

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A refrigerating apparatus comprisinga plurality of substantially flat freezing shelves each having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into one of said reservoirs, a food storage cooling refrigerant evaporating chamber into which the refrigerant from one of said reservoirs flows, the refrigerant flowing in series through said expansion device,

through each of said reservoirs in turn and.

through said chamber, evaporated refrigerant discharge means for said chamber, and the conduits for conveying refrigerant from said reservoirs communicating therewith above the bottoms thereof to trap a quantity of liquid refrigerant therein. 1

from one of said reservoirs overflow, the refrigerant flowing in series first through said expansion device then through each of said reservoirs in turn and then through said chamber, evaporated refrigerant discharge means for said chamber, and the conduits for conveying refrigerant from said reservoirs communicating therewith above the bottoms thereof to trap a quantity of liquid refrigerant therein.

3. A refrigerating apparatus comprising a plurality of substantially fiat freezing shelves each having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into one of said reservoirs, a food storage cooling refrigerant evaporating chamber surrounding said shelves and shielding said shelves from the circulation of air, and into which the refrigerant fromone of said reservoirs overflow, the refrigerant flowing in series'flrst through said expansion device then through each of said reservoirs in turn and then through said chamber, evaporated refrigerant discharge means for said chamber, and the conduits for conveying refrigerant from said reservoirs communicating therewith above the bottoms thereof to trap a quantity of liquid refrigerant therein.

4. A refrigerating apparatus comprising a freezing shelf having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into said reservoir, 2. food storage cooling refrigerant evaporating chamber into which the refrigerant from said reservoir flows, the refrigerant flowing in series through said expansion device, through said reservoir and through said chamber, a heat exchanger through which high pressure refrigerant liquid flows to said expansion device and evaporated refrigerant discharge means for said chamber connected to said heat exchanger and the conduit for conveying the refrigerant from said reservoir. communicating therewith above the bottom thereof to trap a quantity of liquid refrigerant therein.

5. A refrigerating apparatus comprising a freezing shelf having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into said reservoir, 9. food storage cooling refrigerant evaporating chamber shielding said shelf from circulation of air, and into, which said reservoir overflows, the refrigerant flowing in series first through said expansion device then through said reservoir and then through said chamber, a heat exchanger through which high a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into said reservoir, a food storage cooling refrigerant evaporating chamber surrounding said shelf and shielding said shelf from the circulation of air, and into which said reservoir overflows, the refrigerant flowing in series first through said expansion device then through said reservoir and then through said chamber, a heat exchanger through which high pressure refrigergo ant liquid flows to said expansion device and evaporated refrigerant discharge means for said chamber connected to said heat exchanger and the conduit for conveying the refrigerant from said reservoir communicating therewith above the bottom thereof to trap a quantity of liquid refrigerant therein.

'7. A refrigerating apparatus comprising a substantially flat freezing shelf having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into said reservoir, a food storage cooling refrigerant evaporating chamber shielding said shelf from circulation of air, a refrigerant flow pipe depending from said shelf into said chamber and having its inlet extending into said reservoir above the bottom thereof, the refrigerant flowing in series first through said expansion device then through said reservoir then over the edge of the inlet of said pipe, thence through said pipe into said chamber, and evaporated refrigerant discharge means for said chamber.

8. A refrigerating apparatus comprising a substantially flat freezing shelf having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into said reservoir, a food storage cooling refrigerant evaporating chamber surrounding said shelf and shielding said shelf from circulation of air, a refrigerant flow pipe depending from said shelf into said chamber and having its inlet extending into said reservoir above the bottom thereof, the refrigerant flowing in series first through said expansion device then through said reservoir then over the edge of the inlet of said pipe, thence through said pipe into said chamber, and evaporated refrigerant -discharge means for said chamber.

9. A refrigerating apparatus comprising a plurality of substantially flat freezing shelves each having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into said reservoirs, a food storage cooling refrigerant evaporating chamber into which the refrigerant from said reservoirs flows, a pipe depending from one of said shelves to the next succeeding shelf, another pipe extending from one of said shelves to said chamber, the inlets of said pipes extending above the bottoms of said shelves, the refrigerant 7o flowing in series through said expansion device,

I. plurality of substantially flat freezing shelves each having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging refrigerant into said reservoirs, a food storage cooling refrigerant evaporating chamber shielding said shelves from circulation of air, and into which said reservoirs overflow, a pipe depending from one of said shelves to the next succeeding shelf, another pipe extending from one of said shelves to said chamber, the inlets of said pipes extending above the bottoms of said shelves the refrigerant flowing in series first through said expansion device then through each of said reservoirs and pipes in turn, and then through said chamber, and evaporated refrigerant discharge means for said chamber.

11. A refrigerating apparatus comprising a plurality of substantially flat freezing shelves each having a reservoir for maintaining a quantity of liquid refrigerant therein, a refrigerant expansion device discharging, refrigerant into said reservoirs, a food storage cooling refrigerant evaporating chamber surrounding said shelves and shielding said shelves from the circulation of air, and into which said reservoirs overflow, a pipe depending from one of said shelves to the next succeeding shelf, another pipe extending from one of said shelves to said chamber, the inlets of said pipes extending above the bottoms of said shelves, the refrigerant flowing in series first through said expansion device then through each of said reservoirs and pipes in turn and then through said chamber, and evaporated refrigerant discharge means for said-chamber.

12. An evaporator for a refrigerating system comprising a freezing shelf for receiving and supporting a receptacle adapted to contain a substance to be congealed or frozen, said shelf having a reservoir thermally associated therewith and adapted to receive liquid refrigerant, means for conveying refrigerant to said shelf, an air cooling refrigerant evaporating chamber shielding said shelf from circulating air, a conduit extending from said shelf to said chamber for conveying refrigerant from the reservoir into said chamber, means providing an outlet for refrigerant evaporated in said chamber, and said conduit communicating with said reservoir above the bottom thereof for trapping a quantity of liquid refrigerant in said freezing shelf.

13. An evaporator for a refrigerating system comprising a plurality of superimposed freezing shelves for receiving and supporting receptacles adapted to contain a substance to be congealed or frozen, said shelves having a reservoir thermally associated therewith and adapted to receive liquid refrigerant, means for conveying refrigerant to said shelves, a substantially U-shaped air cooling refrigerant evaporating chamber extending around said shelves for shielding the shelves from circulating air, a conduit extending from one of said shelves to said chamber for conveying refrigerantfrom the reservoir of said one of said shelves into the lowermost portion of said U- shaped chamber, means providing an outlet for refrigerant evaporated in said chamber, and said conduit communicating with said reservoir above the bottom thereof for trapping a quantity of liquid refrigerant in said one of said plurality of freezing shelves.

14. An evaporator for a refrigerating system comprising afreezing shelf for receiving and supporting a receptacle adapted to contain a substance to be congealed or frozen, said shelf having a reservoir thermally associated therewith and adapted to receive liquid refrigerant, means amass I 5 for conveying refrigerant to shelf, an air cooling refrigerant evaporating chamber, a conduit extending from said shelf downwardly to said chamber for conveying refrigerant from the reservoir into said chamber, means providing an outlet for refrigerant evaporated in said chamfreezing shelf. c

I A. KUCHER.- 

